The present invention relates to a thermoplastic polyester resin composition, and more particularly to a thermoplastic polyester resin composition wherein a modified polyolefin elastomer is used as a modifier.
When compared with other industrial materials such as glass, metals, wood, concrete, thermoplastic polyester resin compositions have various features such as inexpensiveness lightness, high specific strength, high chemical stability, high moldability. and therefore they are widely used for industrial products, domestic utensils and parts of both.
Under the recent development of industry and technology, various techniques have been developed and studied to improve the properties and qualities of the compositions by reinforcement means with glass fibers or filers and/or various polymer alloy technologies.
Polyethylene terephthalate (hereinafter referred to as xe2x80x98PETxe2x80x99), a kind of thermoplastic polyester resin, is superior in heat resistance, chemical resistance, mechanical characteristics and electric characteristics, additionally transparency and barrier ability whereby it is widely used for bottles and packaging material for food.
However, one of the shortcomings of PET is inferiority in impact resistance, and thereby the uses of PET as a material for injection molding is markedly limited. In fact, only glass fiber reinforced materials are practically used as a material for injection molding.
Therefore, improvement of PET""s properties by inexpensive and easy means is expected in order to overcome the limited uses of PET as a molding material. If such techniques are developed, the uses of thermoplastic polyester resin will be widened to electric home appliances, construction materials, automobile parts and the like.
Another problem is that a large number of various PET bottles being dumped by industries etc. have few uses for recycling due to the reasons mentioned above, although it is possible to collect them.
In particular, it is a big problem that recycled PET bottles have few uses, although collecting the bottles is easy and safe, and the bottles are high in purity as a raw material since they are originally vessels for drinks and the like.
The present invention has been intended to achieve the above-mentioned purposes.
The inventors of the present invention developed a carboxyl-modified metallocene catalyzed polyolefin elastomer (polyolefin elastomer polymerized by using a metallocene catalyst) and a glycidyl methacrylate adduct to the elastomer for inexpensive and easily manufacturable modifier of a thermoplastic polyester resin, and thereby developed a novel thermoplastic polyester resin which is superior in impact resistance.
The present invention thus increases the uses for recycled thermoplastic polyester resins.
Additionally, the inventors succeeded in developing a thermoplastic polyester resin wherein inorganic fillers are mixed.
The present invention is embodied in accordance with the following constitutions and particulars.
The invention according to Claim 1 is a thermoplastic polyester resin composition comprising 90 to 60 parts by weight of a thermoplastic polyester resin and 10 to 40 parts by weight of a carboxyl-modified metallocene catalyzed polyolefin elastomer.
The above-mentioned composition improves a thermoplastic polyester resin markedly in its mechanical characteristics.
The invention according to Claim 2 is the thermoplastic polyester resin composition according to Claim 1, wherein the aforementioned thermoplastic polyester resin is polyethylene terephthalate.
The above-mentioned composition provides a highly impact-resistant thermoplastic polyester resin composition, wherein polyethylene terephthalate, which is frequently used for PET bottles, is the main material.
The invention according to Claim 3 is the thermoplastic polyester resin composition according to Claim 2 wherein the aforementioned metallocene catalyzed polyolefin elastomer is ethylene.xcex1-olefin copolymer hating 5 to 30 wt. %, based on the weight of the ethylene, of xcex1-olefin comonomer and the basic structure (repeating unit) of the elastomer is [CH2xe2x80x94CH2]n.[CH2xe2x80x94CHR]m (R is a side chain represented in CH3.[CH2]L, L is 3 to 8 inclusive.).
The above-mentioned composition improves impact resistance of a thermoplastic polyester resin since the elastomer comprises the side chains with an appropriate length. Moreover, appropriate flexibility of the resins is attained.
The invention according to Claim 4 is a filled (inorganic-filler-mixed) thermoplastic polyester resin composition comprising 100 parts by weight of the thermoplastic polyester resin composition according to Claims 3 and 10 to 500 parts by weight of an inorganic filler.
The above-mentioned composition improves a thermoplastic polyester resin composition markedly in its mechanical strength, such as its flexural modulus, by the action of the inorganic or mineral filler. In addition, the mixing of a thermoplastic polyester resin composition and an inorganic filler is rendered easy and uniform since the mixing ratio of the composition and the filler is appropriate. Furthermore, the polyolefin elastomer is improved in interfacial contact with the inorganic filler and thereby retains even more preferable mechanical characteristics since the whole elastomer is modified with an acid uniformly.
The invention according to Claim 5 is the thermoplastic polyester resin composition according to Claim 4, wherein a carboxyl-modified metallocene catalyzed polyolefin elastomer is modified with 0.01 to 1.0 wt. %, based on the weight of the elastomer, of maleic anhydride or maleic acid.
The above-mentioned composition enables the whole metallocene catalyzed polyolefin elastomer to be uniformly modified with an acid under the limited conditions, and therefore the elastomer is improved in the bonding with a thermoplastic polyester resin and inorganic fillers. In addition, with the use of a twin-screw extruder, it is possible to facilitate the acid modification of the polyolefin elastomer and the mixing of the elastomer with a thermoplastic polyester resin and additionally an inorganic filler.
The inventions according to Claims 6 to 8 are the inventions wherein the invention according to Claim 2 is combined with the inventions according to Claims 4 and/or 5.
The invention according to Claim 9 is the thermoplastic polyester resin composition according to Claim 1, wherein the aforementioned thermoplastic polyester resin is a mixture of polyethylene terephthalate and polybutylene terephthalate at a weight ratio of from 95:5 to 5:95.
The above-mentioned composition provides a highly impact-resistant thermoplastic polyester resin composition, wherein the main material is the mixture of polyethylene terephthalate and polybutylene terephthalate at a wide range of weight ratios of from 95:5 to 5:95 in consideration of flowability, moldability and heat resistance depending on its uses.
The inventions according to Claims 10 to 15 are the inventions according to Claims 3 to 8, wherein the mixture of polyethylene terephthalate and polybutylene terephthalate is used in place of the polyethylene terephthalate in the inventions according to Claims 3 to 8, in correspondence to the difference between the invention according to Claim 9 and the invention according to Claim 2.
The invention according to Claim 16 is a thermoplastic polyester resin composition comprising 90 to 60 parts by weight of a thermoplastic polyester resin and 10 to 40 parts by weight of a glycidyl methacrylate adduct to a metallocene catalyzed polyolefin elastomer.
The above-mentioned composition provides a highly impact-resistant thermoplastic polyester resin composition comprising 90 to 60 parts by weight of thermoplastic polyester resin and 10 to 40 parts by weight of the glycidyl methacrylate adduct to a metallocene catalyzed polyolefin elastomer which is excellent in impact resistance.
The inventions according to Claims 17 to 30 are the inventions according to Claims 2 to 15, wherein the glycidyl methacrylate adduct is used in place of a carboxyl-modified metallocene catalyzed polyolefin elastomer in the inventions according to Claims 2 to 15 in correspondence to the difference between the invention according to Claim 16 and the invention according to Claim 1.